A DVR generally called a hard disk recorder (HDR) or a personal video recorder (PVR) stores digital broadcasting signals as well as analog broadcasting signals using a large capacity storage device such as a hard disk drive (HDD), and allows a user to reproduce and view the stored broadcasting signals when necessary.
The DVR has a basic function of storing a program transmitted from a broadcasting station and viewing the stored program, but is discriminated from a related art video cassette recorder (VCR) in that it records data in an HDD and reproduces the data stored in the form of a file as in a computer, and has a central processing unit (CPU) and an operating system (OS) for reproduction, a memory chip containing a reproduction software, and the HDD.
That is, the DVR includes a television (TV) tuner, a storage and reproduction software, a modem, and an HDD. The DVR has a great advantage in that it converts a TV program into digital signals, stores the digital signals in the HDD, and reproduces the stored digital signals when necessary using the HDD that is adopted for a computer.
Moreover, the DVR provides more improved functions compared to a related art analog VCR by providing various functions such as a time shift function, and an instant replay function while live broadcasting is viewed besides a recording function, which is a basic function. Particularly, an advantage that high definition (HD) level high quality digital broadcasting can be stored in an HDD and viewed whenever necessary, and various additional service functions provide great usefulness to a user.
The above-described DVR can be applied to a monitoring system, and is a security solution system of high resolution that can record monitored images for a long time, and perform swift searching and clear reproducing of the recording images by converting analog image signals input from a plurality of monitoring cameras into digital signals, and compressing the digital signals. Demand for the DVR increases in a financial organization or an airport indispensably requiring high resolution security.
The above-described apparatus to which a monitoring system is applied uses technology of outputting a moving image and a voice of a visitor through a door bell to a corresponding image display device, or of detecting and storing movement of a visitor, and checking stored images using an image display device. The above-described apparatus can be a digital image display device having a DVR system, including a DVR having an HDD, a camera for monitoring movement of a person, and a display system.
However, an image display device of a related art keeps storing even unnecessary images as continuously detected movements are stored when a monitoring system is still in operation, which causes unpleasant feeling to a user who reproduces afterward and a storage capacity is utilized inefficiently.